I want to remove the green crap in my engine bay...

Meguiars engine cleaner and meguiars dressing didn't help much...

Does it need to work in longer?

pics atm;

 

Looks like the protective wax that is normally removed at PDI. You could try some Autosmart Tardis or try working the degreaser in with a plastic bristled brush.

 

Looks like the protective sealant , I would use some TFR (traffic film remover ) watered down 1 to 20 with a stiff brush , then use a radiator brush on the had to get to area`s then rinse off with another clean brush !!

Good Luck

 

looks like aircon dye to me